1. Technical Field
The present invention relates to a semiconductor device including a wiring substrate having a semiconductor chip mounted thereto, and a heat radiator. In particular, the invention relates to a semiconductor device having high heat radiation performance and high reliability.
2. Related Art
Semiconductor chips, such as drivers for display panels, need to secure a sufficient heat radiation ability in being mounted on wiring substrates due to the high heat value. For example, a technique for enhancing heat radiation performance is disclosed in JP-A-2002-124607 (19 to 21 paragraphs and FIG. 2), in which the upper surface of a semiconductor chip is adhesively bonded to a metallic chassis with a heat radiation sheet interposed therebetween, and a heat radiator is fixed to the rear surface of a flexible substrate in a semiconductor device including the flexible substrate having a semiconductor chip mounted on its surface.
In the technique disclosed in JP-A-2002-124607, all most all forces applied either the semiconductor chip or the metallic chassis are directed to a connected portion between the upper surface of the semiconductor chip and the metallic chassis. As a result, a connected portion between the semiconductor chip and the wiring substrate may be peeled off.
In order to solve the problem, there is also a method in which the heat radiator positioned on the surface of the wiring substrate is adhesively bonded to the surface of the wiring substrate. In this case, however, a force applied either the heat radiator or the wiring substrate in the face direction is directed to wiring lines formed on the surface of the wiring substrate. As a result, the wiring lines may be peeled off from the base of the wiring substrate.
In this manner, it is difficult to satisfy both the heat radiation performance and the reliability.